Siemens SINUMERIK 840D sl Function Manual page 1343

Priority of the signals
The signals are scanned in ascending order starting at I0. Therefore, the retraction motion
(SR) has the highest priority and the feedrate F7 the lowest priority.
SR and ST end the feedrate motions that were activated with F2 to F7.
SR also ends ST, i.e. the complete function.
The signal with the highest priority determines the current feedrate.
The response to loss of the respective highest-priority input (F2 - F7) can be defined with the
machine data:
MD21230 $MC_MULTFEED_STORE_MASK (storage behavior for the "Multiple feedrate
values in one block" function)
Bit
2 ... 7
The end-of-block criterion is satisfied when:
● The programmed end position is reached
● The retraction motion ends (SR)
● The dwell time elapses (ST)
Hardware assignment
The input byte for the "Multiple feedrate values in one block" function can be assigned a
maximum of two digital input bytes or comparator input bytes of the NCK I/O:
MD21220 $MC_MULTFEED_ASSIGN_FASTIN (assignment of the input bytes of the NCK I/O
for "Multiple feedrate values in one block"), bit 0 ... 15
The input bits can also be inverted:
MD21220 $MC_MULTFEED_ASSIGN_FASTIN, bit 16 ... 31
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Value Meaning
0 With the loss of the respective highest-priority input, the associated feedrate is not
retained (default setting).
1 Set bit 2 to 7 ensures that the associated feedrate (F2 to F7) that was selected by
the respective highest-priority input signal is also retained when there is a loss of
the input signal and a lower-priority input is active.
V1: Feedrates
17.4 Feedrate control
1343